Guides · Dartboard dimensions · 9 min read
Dartboard dimensions and numbers: the official layout
Official dartboard dimensions come from the WDF playing rules, and the PDC’s rulebook asks for the same board. Here you get every measurement in mm and inches, the number order and a quick way to check your own board.
In short
- 451 mm across, with a 340 mm scoring area.
- 8 mm rings for doubles and trebles, 12.7 mm bullseye.
- 20 at the top, then 1, 18, 4, 13 clockwise.
- Bull at 1.73 m, oche 2.37 m from the board.
Dartboard numbers
What order are the numbers on a dartboard?
Clockwise from the top, the dartboard numbers run 20, 1, 18, 4, 13, 6, 10, 15, 2, 17, 3, 19, 7, 16, 8, 11, 14, 9, 12, 5. Each of the 20 segments covers 18 degrees, and the 20 always sits at the top.
Read it like a clock
- Landmarks: 20 at 12 o’clock, 6 at 3, 3 at 6 and 11 at 9.
- Neighbours of 20: 5 on the left, 1 on the right. A dart that drifts off the treble 20 usually lands in one of them.
- Opposite pairs: 20 and 3, 1 and 19, 18 and 7, 4 and 16, 13 and 8, 6 and 11, 10 and 14, 15 and 9, 2 and 12, 17 and 5.
- Learning them: a few rounds of Around the Clock, 1 to 20 in order, beat any mnemonic.
The idea behind it
Why are the numbers on a dartboard in that order?
The order punishes inaccuracy. Almost every high number has low numbers beside it, so a dart that misses the big score by a few millimetres costs a lot of points.
- High next to lowThe 20 sits between 5 and 1, the 17 between 2 and 3, the 18 between 1 and 4.
- Almost as harsh as it getsAdd up the gaps between all 20 pairs of neighbours and you get 198. No circle of 1 to 20 can go above 200.
- Not perfectly evenThe 19 has bigger neighbours than the 20, which is why some players aim at the treble 19. T20 or T19 weighs it up.
- Who designed itOften credited to Brian Gamlin of Bury, 1896. Darts historian Patrick Chaplin found no evidence he existed and credits Thomas William Buckle, a Yorkshire craftsman, in 1913.
Dartboard size
What are the official dartboard dimensions?
A regulation dartboard is 451 mm (17¾ in) across, with a 340 mm scoring area and 8 mm double and treble rings. The WDF rules give every measurement a tolerance, and the PDC’s rulebook, published by the Darts Regulation Authority, asks for the same bristle board.
- 451 mmboard diameter
- 340 mmscoring area
- 8 mmdouble and treble rings
- 12.7 mmbullseye
| Measurement | Metric and tolerance | Imperial |
|---|---|---|
| Board diameter | 451.0 mm ± 3.0 | 17¾ in |
| Scoring area, across the outside of the double wire | 340.0 mm ± 0.5 | 13⅜ in |
| Bull centre to outside of the double wire | 170.0 mm ± 0.2 | 6.69 in |
| Bull centre to outside of the treble wire | 107.4 mm ± 0.2 | 4.23 in |
| Double and treble ring, inside width (wire boards) | 8.0 mm ± 0.2 | 0.31 in (about 5⁄16 in) |
| Double and treble ring, strip boards, apex to apex | 10.0 mm ± 0.2 | 0.39 in |
| Bullseye (50), inside diameter | 12.7 mm ± 0.2 | ½ in |
| 25 ring (outer bull), inside diameter | 31.8 mm ± 0.3 | 1¼ in |
| Wire thickness | 1.27 to 1.85 mm ± 0.2 | 0.05 to 0.07 in |
| Bull rings made from strip, wall thickness | 1.6 mm at most ± 0.2 | 0.06 in |
| Board thickness | about 38 mm, not in the rules | about 1½ in |
107 or 107.4? Many sites give the treble ring as 99 to 107 mm from the centre, a rounded drawing value. The WDF figure is 107.4 mm to the outside of the treble wire.
Measuring your board
How do you check that a dartboard is regulation size?
Measure the scoring area, one narrow ring and the bull, then check that the 20 is black and at the top. A steel ruler does most of it, and a calliper makes the 8 mm rings easier.
- Measure across the scoring areaOutside of the double wire to outside of the double wire, straight through the bull. You want 340 mm, give or take 0.5 mm. That tells you more than the overall diameter, which may be 3 mm off.
- Check a double and a trebleMeasure inside the wires: 8 mm on a wire board, or 10 mm apex to apex on a board made with thin strips.
- Measure the bull12.7 mm inside the bullseye wire, 31.8 mm for the 25 ring. The tolerances are only 0.2 and 0.3 mm.
- Check the orientationThe 20 sits at the top over a black segment. If the number ring went back crooked after you turned the board, lift it off and line it up again.
- Check height and distanceBull centre 1.73 m above the floor, oche 2.37 m from the board face. Measure from the surface you stand on, mat included.
How to hang a dartboard walks you through both measurements. If your board fails the check, or it is a thin paper or cork board, the dartboard buying guide shows what to look for.
Colours
What colours are on a dartboard?
The singles alternate black and a light colour, usually white or cream. The doubles and trebles alternate red and green, and the 20 is always a black segment at the top.
- Black segments: 20, 18, 13, 10, 2, 3, 7, 8, 14 and 12. Their doubles and trebles are red.
- Light segments: 1, 4, 6, 15, 17, 19, 16, 11, 9 and 5. Their doubles and trebles are green.
- Bull: a red bullseye inside a green 25 ring.
- Number ring: scores nothing. On most bristle boards it lifts off, so you can turn the board to spread the wear. Dartboard care explains how.
Scoring areas
What does each ring on a dartboard score?
A dart scores the area its point is in: the number once in a single, twice in the outer narrow ring and three times in the inner one. The two rings in the middle score 25 and 50.
| Area | Score | Areas |
|---|---|---|
| Single | 1 to 20 | 40 |
| Treble | 3 to 60 | 20 |
| Double | 2 to 40 | 20 |
| 25 ring | 25 | 1 |
| Bullseye | 50, a double | 1 |
| Outside the double wire | 0 | – |
- 82 scoring areasAn inner and an outer single, a double and a treble for each number make 80, plus the 25 ring and the bullseye. Count both singles as one bed and you get 62 targets.
- Which side of the wireUnder WDF rules the score comes from the side of the wire where the point went in. A bounce-out, or a dart that falls out before the score is called, scores nothing.
- Bull as a doubleThe bullseye is double 25, so a leg of 501 can end on it. The 25 ring is a single and never finishes a leg with a double out.
- Treble or tripleBoth words mean the same ring. British players say treble, many apps say triple, and the glossary of darts terms covers the rest.
Maths of the board
What are the highest and lowest scores on a dartboard?
The highest score with one dart is 60, the treble 20, and the highest with three darts is 180. The lowest score that counts is 1, and a dart outside the double wire scores 0.
- 60best single dart, the treble 20
- 180best visit, three treble 20s
- 170highest checkout with a double
- 1lowest score that counts
- Bull beaten: at 50, the bullseye scores less than the trebles of 17, 18, 19 and 20.
- Top finish: 170 is the biggest checkout with a double. The checkout chart lists every finish below it.
- 43 values: one dart can score 43 different amounts from 1 to 60. It can’t make 23, 29, 31, 35, 37, 41, 43, 44, 46, 47, 49, 52, 53, 55, 56, 58 or 59.
- Impossible visits: three darts can make any total from 0 to 162. Above that, 163, 166, 169, 172, 173, 175, 176, 178 and 179 can’t be scored.
Board types
Are all dartboards laid out the same way?
The board on this page is the standard for all steel-tip competition. Rulebooks call its numbering the 1 to 20 clock pattern, and in the UK it is also known as the London board or trebles board.
- London boardThe standard, with treble ring, 25 ring and bullseye. It grew out of the Yorkshire board, and the National Darts Association made it the standard in England in the 1920s.
- Regional boardsYorkshire and Manchester boards have doubles and a bull but no treble ring, and the Manchester log-end board is smaller too. The London Fives board has 12 segments, numbered only 5, 10, 15 and 20.
- Soft-tip boardsHoles instead of bristle and the same number order, but larger beds and a throw line at 2.44 m. Steel-tip vs soft-tip compares the two.
- Camera scoringNeeds a standard board. Sridu finds the bull, the rings and the wires in each camera picture, then maps every dart onto exactly this layout.
Sources: WDF Playing and Tournament Rules, 20th revised edition (PDF), DRA Rule Book, Patrick Chaplin on the order of the dartboard numbers.
FAQ
Dartboard dimensions: common questions
How big is a regulation dartboard?
The regulation dartboard size is 451 mm (17¾ in) in diameter, with a tolerance of 3 mm either way. The scoring area inside the outer double wire is 340 mm (13⅜ in) across, and the rest is the number ring.
Which number is at the top of a dartboard?
The 20, on a black segment, with the 5 to its left and the 1 to its right. The 3 is at the bottom, the 6 on the right and the 11 on the left.
How many segments does a dartboard have?
20 numbered segments of 18 degrees each. Split into their parts, that gives 82 scoring areas: two singles, a double and a treble for each number, plus the 25 ring and the bullseye.
How wide are the double and treble rings?
8 mm on the inside, measured from wire to wire, with a tolerance of 0.2 mm. Boards made with thin strips instead of round wire measure 10 mm from apex to apex.
How thick is a dartboard?
The rules don’t set a thickness. Standard bristle boards are about 38 mm (1½ in) thick and weigh around 5 kg, while cheap paper or cork boards are thinner and wear out much faster.
Is the bullseye a double?
Yes. The bullseye scores 50 and counts as double 25, so you can finish a leg on it, while the 25 ring around it is a single. Darts for beginners explains how the double finish in 501 works.
Put the board to work
You know the dartboard dimensions and every number on it, so let Sridu keep the score. Open it in Chrome or Edge, type in your scores or add a few webcams, and play X01, Around the Clock and 29 other game modes. It’s free and needs no account.